We report low-temperature measurements of dissipation in megahertz-range, suspended, single-crystal nanomechanical oscillators. At millikelvin temperatures, both dissipation (inverse quality factor) and shift in the resonance frequency display reproducible features, similar to those observed in sound attenuation experiments in disordered glasses and consistent with measurements in larger micromechanical oscillators fabricated from single-crystal silicon. Dissipation in our single-crystal nanomechanical structures is dominated by internal quantum friction due to an estimated number of roughly 50 two-level systems, which represent both dangling bonds on the surface and bulk defects.
@article{arxiv.cond-mat/0603691,
title = {Quantum Friction in Nanomechanical Oscillators at Millikelvin Temperatures},
author = {Guiti Zolfagharkhani and Alexei Gaidarzhy and Seung-Bo Shim and Robert L. Badzey and Pritiraj Mohanty},
journal= {arXiv preprint arXiv:cond-mat/0603691},
year = {2009}
}
Comments
5 pages, two-column format. Related papers available at http://nano.bu.edu